Customer Acquisition Cost (CAC) Calculator
Calculate how much it costs to acquire a new customer. Enter your total sales and marketing spend, the number of new customers acquired, and optionally your customer lifetime value to see the LTV:CAC ratio.
CAC by Channel
What is Customer Acquisition Cost (CAC)?
Customer Acquisition Cost (CAC) is the total cost of winning a new customer, calculated by dividing all sales and marketing spend over a period by the number of new customers acquired in that same period. It is one of the most important unit economics metrics for any business that actively markets for growth — particularly SaaS companies, e-commerce, and subscription businesses where revenue per customer accumulates over time rather than in a single transaction.
CAC is most meaningful when compared to Customer Lifetime Value (LTV), the total revenue a customer generates over their relationship with the business. The LTV:CAC ratio measures the return on customer acquisition investment. A ratio of 3:1 is generally considered healthy — meaning each customer generates three times what it cost to acquire them. A ratio below 1:1 means the business is losing money on each customer acquired, an unsustainable position. A ratio above 5:1 may suggest the business is underinvesting in growth opportunities.
Breaking CAC down by marketing channel allows businesses to identify which acquisition channels are most cost-efficient. Paid search may have a lower CAC than events; organic search (SEO) may have the lowest CAC of all channels once content is established. Channel-level CAC analysis guides marketing budget allocation, helping teams shift spend toward the most efficient channels and away from those with unacceptably high acquisition costs relative to the LTV they generate.
CAC Formula
How the CAC Calculator Works
Formula, assumptions, and calculation steps for this business tool.
Methodology
Business calculators combine revenue, cost, margin, productivity, or pricing inputs into operating metrics that can be compared across scenarios.
Calculation Steps
- Enter the business quantities, prices, costs, or rates.
- Separate fixed values from variable values where the formula requires it.
- Calculate the metric using standard business arithmetic.
- Return the headline result with supporting totals or percentages.
Assumptions and Limits
- Inputs should represent the same period or business unit.
- One-time and recurring costs should not be mixed unless the calculator explicitly supports them.
- Results are planning estimates and may differ from accounting statements.
Frequently Asked Questions
A good CAC depends on your industry and LTV. The benchmark LTV:CAC ratio is 3:1 — meaning each customer should generate 3x what it cost to acquire them. A ratio below 1:1 means you are losing money on each customer.
Include all sales and marketing expenses: ad spend, salaries of sales and marketing staff, tools/software, content creation, agency fees, events, and any other costs directly tied to customer acquisition.
Improve conversion rates on landing pages, invest in organic channels (SEO, content), leverage referral programs, optimise ad targeting, and focus on retention to increase LTV which makes higher CAC more viable.
LTV:CAC measures how much value a customer generates relative to what it cost to acquire them. A 3:1 ratio is healthy. Below 1:1 is unsustainable. Above 5:1 may indicate underinvestment in growth.
Real-World Applications
Common Mistakes
LTV:CAC Ratio Interpretation
| LTV:CAC | Interpretation | Action |
|---|---|---|
| < 1:1 | Losing money on every customer | Immediate pricing or cost review required |
| 1:1 – 2:1 | Barely recovering acquisition cost | Reduce CAC or improve retention/LTV |
| 3:1 | Healthy — industry benchmark | Invest in growth; monitor payback period |
| 4:1 – 5:1 | Excellent capital efficiency | Consider increasing acquisition spend |
| > 5:1 | Possibly underinvesting in growth | Accelerate acquisition while returns are strong |
References
- Skok, D. Startup Metrics for Pirates — AARRR. forentrepreneurs.com.
- Gupta, S. et al. Valuing Customers. Journal of Marketing Research, 2004.
- Andreessen Horowitz (a16z). SaaS Metrics 2.0. a16z.com.
- Fader, P. S. & Hardie, B. G. S. Customer-Base Valuation in a Contractual Setting. Marketing Science, 2010.
- Kotler, P. & Keller, K. L. Marketing Management, 16th ed. Pearson, 2022.
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